Kalliston felt his boot crunch through something fragile, and looked down. A ribcage lay there, shattered by his heavy tread, as brittle and black as coal. It wasn’t big enough to be an adult’s.

He looked further up the street. Bones were strewn everywhere ahead, all of them human-sized.

Briefly, something flickered on his helm-display. Kalliston was instantly alert, though the signal, a threat rune on the edge of his armour’s detector range, disappeared as soon as it had come.

‘Captain,’ voxed Phaeret, one of his squad members. ‘You’ll want to see this.’

Kalliston blink-clicked an acknowledgement. The threat rune didn’t make another appearance on his display. Possibly a false reading, or some malfunction in the long-range augurs in his armour.

Both those possibilities were unlikely. Kalliston kept his boltgun muzzle in firing position as he walked towards Phaeret’s location marker, and his senses remained alert. He was perfectly aware of the danger, and perfectly aware of the opportunity.

Something else was alive on Prospero.

‘SO HOW DID you feel, seeing the destruction of your home world?’

The question surprises me. What does it matter, what I feel about anything? If this is an interrogation by a member of the forces occupying the planet, I would have expected questions on the disposition of the remains of my Legion, on the lingering capabilities of the survivors – something, at least, about military matters.

But then, there is much that is strange about this interrogation. I have the overwhelming feeling that I am not just here for the information I can provide. No, this unseen questioner wants something else.

‘Uncomfortable,’ I reply. ‘But nothing more than that. We knew something of what to expect. My deputy is a seer, and he had made us aware of what had happened in its broadest outline.’

At the mention of Arvida, I wonder if he still lives. Perhaps he is being questioned in a cell like this too, or maybe he lies dead in the glass dust of the city.

‘Uncomfortable?’ he repeats.

The word seems to irritate him, and the breathing becomes more erratic.

‘You were spineless,’ he says, and the voice is harsh and accusatory. ‘You come back here, like damned reclamators, picking through the rubble of what you let be destroyed. If this had been my world I’d never have left it. I’d have killed any invader who dared come close to it, and damned be my primarch’s orders. You were weak, Captain Kalliston. Weak.’

He insists on the term, spitting it out. I sense his body coming closer. He is looming in the dark now, just beyond the ends of my chair-arms. Exhalations brush against my face, hot and caustic, like the breath of a dog.

‘If we’d known–’ I begin, starting to defend myself. I don’t know why I feel the urge to do this. It doesn’t matter what the questioner thinks of me, for my own conscience is untroubled.

‘If you’d known!’ he roars, cutting short my half-hearted response. Droplets of spittle hit my face. For a moment I think he’s flown into a rage, but then I realise he’s laughing. ‘Listen to yourself, Thousand Son. You’ve always been so proud, strutting across worlds conquered by the prowess of other Legions, glorying in your superior understanding of what we uncovered for you. Not for you the dirty work of fighting with your hands. Oh, no. There were always other fighters to do that for you, to take on the danger at close-quarters, freeing you up to spend those hours in your libraries. Did you ever guess how much we all held you in contempt?’

‘We knew well enough,’ I say.

It’s perfectly true – we knew just how much our brothers mistrusted us, and as a result worked hard not to provoke them. He’s entirely wrong that we gloried in our superior understanding. Instead, we hid it, tried to show it as little as possible. Those instincts, as it turns out, may well have been mistaken.

‘You knew? You could have fought like warriors, rather than drift into witchery. You had choices. I don’t understand you.’

Did we have choices? Prospero was a world soaked in the psychic possibility of the Great Ocean. We were all touched by it, for better or worse. I don’t think we could have turned down the opportunities that gave us, even though we knew it made the other Legions uneasy.

Ultimately, though, the question is pointless. We did what we did, and no power in the universe has ever been able to undo the past.

‘We fought,’ I reply, remembering the conquest of Shrike, when Magnus himself had led us in war. He’d been magnificent, unstoppable, just as much as Russ or Lorgar, every bit the vision of the Emperor’s most favoured son. ‘We played our part.’

‘No longer,’ comes the riposte, savage with satisfaction. ‘Your part is over. Your pyramids are destroyed, and your bastard primarch’s back broken.’

He hates us. The hatred has not diminished with the humbling of my Legion. That may be why he brought me here. To gloat. My mind-sight is beginning to return, and I sense enormous frustration boiling within him. He has been left behind while others have departed for further conquest. This is one source of his anger. Soon, he will vent it on me.

But I cannot believe that is the only motivation. I am aware still how little I know. Why was Prospero destroyed? What, exactly, brought that doom upon us? The ignorance of that is more torture than anything this interrogator has planned for me. To die without uncovering those truths would be the most shameful way to go, and one that would vindicate Arvida’s doubts about coming back.

Can I use the instability in my questioner to my advantage? Would he let slip secrets if I goaded him? A dangerous course of action – his cooped-up rage is like that of a beast, wild and indiscriminate. But then, there is little for me to lose. My Legion is scattered, my primarch missing, my home world blasted into a ball of lifeless slag. I would like some answers before he loses control of the furnace within him and ends this conversation for good.

‘Magnus is not dead,’ I say. ‘I would know if he’d died. It was in the hope of finding him that we came back here. You, though, seem to know everything about us and what happened to our planet. You hint at more, things that I can only guess at. Since you know so much, and I know so little, should it not be me asking the questions?’

In the near-complete dark, I make out only the sharpest flash of dirty-grey. A gauntlet plunges out of the shadow and grabs my neck. The fingers squeeze painfully, just below the chin and just above the metal band that holds my head in place.

‘You are preyfor me, traitor,’ comes the bloody rumble of a voice. ‘Nothing more than that. Forget it, and I will end you with agony.’

The threat means little. As I struggle to breathe, though, I realise something else. My aether-drawn powers are returning. They are weak, to be sure, but they are creeping back to me in drabs. Perhaps he knows this, perhaps he doesn’t. In any case, I have a glimmer of a chance now. The longer this thing lasts, the stronger I will become. Maybe, just maybe, strong enough to break these bonds.

The Ungifted Warriors have always underestimated what can be done with the mind, no doubt because we gifted have always been reluctant to use our skills unless pressed by necessity.

He releases his fist, and I gulp in draughts of blood-tanged air. He withdraws, though I can still feel him seething. He keeps his anger on an uncertain leash, as if it were a ravening predator continually tugging at its inadequate restraint.

‘How many were in your squad?’ he asks, recovering his poise with difficulty.

That’s good. I hope he has many such questions. I will answer them all fully, all the while letting my control over the aether return.

‘Nine,’ I say, and though my speech is grudging and surly, in my mind there already kindles an eager anticipation for what is to come. ‘There were nine of us.’